1. Field of the Invention
The present invention relates to a polymerizable composition, an antireflection film using the same, a polarizing plate using the antireflection film, an image display device using the antireflection film or the polarizing plate on the outermost surface of a display, and a water-repellent or oil-repellent film.
2. Description of the Related Art
In image display devices such as a cathode ray tube (CRT), a plasma display panel (PDP), an electroluminescence display (ELD), and a liquid crystal display device (LCD), for the purpose of preventing the occurrence of decrease of contrast or reflected glare of image to be caused due to reflection of external light, an antireflection film is generally disposed on the outermost surface of a display so as to reduce a reflectance utilizing the principle of optical interference. For that reason, besides high antireflection ability, the antireflection film is required to have high antifouling properties against oil-and-fat components such as a fingerprint and sebum, high physical strength (e.g., scratch resistance, etc.), high transmittance, chemical resistance, and weather resistance (e.g., resistance to moist heat or light fastness).
As such antireflection films, films having a single-layer optical interference layer are known. But, from the viewpoint of achieving low reflection, it is the present state that multilayer type antireflection films having plural optical interference layers including a low refractive index layer, a medium refractive index layer, a high refractive index layer, and the like are developed.
In such multilayer type antireflection films, on one hand the low reflection can be achieved, but on the other hand, there is a concern that when the layer thickness or refractive index of each layer fluctuates, the reflected color changes. In particular, when a fingerprint or sebum is attached onto the surface of a coating film on the multilayer type antireflection film, even if it is wiped off, an attached mark is conspicuously viewed as a change of tint due to a change of the refractive index from a reason that the oil-and-fat component remains slightly, as compared with the case where the optical interference layer is a single layer, and thus, the visibility of an image is easily lowered. In consequence, the multilayer type antireflection films are especially required to have high antifouling properties against oil-and-fat components such as a fingerprint and sebum.
As technologies for imparting antifouling properties, there is generally known a method for decreasing a surface free energy on the coating film surface using a silicone compound having a polydimethylsiloxane structure or a fluorine-based compound. For example, it is proposed to impart an antifouling performance using a compound having a long-chain perfluoropolyether (PFPE) chain and a polyfunctional polymerizable unsaturated group (see, for example, JP-A-2009-256597 and Japanese Patent No. 4556151).
However, in view of the fact that such a compound uses PFPE (FLUOROLINK D), manufactured by Solvay Solexis, Inc. as a raw material, it is a compound having two kinds of repeating structures including a repeating structure represented by —(CF2CF2O)m— and a repeating structure represented by —(CF2O)n—. FLUOROLINK D is represented by HOCH2CF2O(CF2CF2O)m(CF2O)nCF2CH2OH.
Incidentally, in the structure of Compound 1 described in paragraph [0020] of JP-A-2009-256597, though the repeating structure is represented by —(CF2CF2O)n—, it is erroneous. Actually, the repeating structure in Compound 1 of Patent Document 1 is known to be composed of two kinds of repeating structures including a repeating structure represented by —(CF2CF2O)m— and a repeating structure represented by —(CF2O)n—.
Taking into consideration an enhancement of surface tension decreasing ability due to an increase of hydrophobic interaction between the PFPE structures, a PFPE structure having a single structure such as a —(CF2CF2O)m— structure was desired. However, as shown in the following production scheme, it was difficult to obtain a repeating structure composed of only a single —(CF2CF2O)m— structure from a production process of FLUOROLINK D (see, for example, Fusso Kagaku Nyumon, Kiso-to-Oyo-no Saizensen 2010 (An Introduction to Fluorine Chemistry, Forefront of Foundation and Application, 2010)).

In addition, in order to impart antifouling properties to the low refractive index layer, more improvements in the antifouling properties and the scratch resistance are required.
Furthermore, a compound having such a PFPE structure, its solubility in a coating solvent or other component in the composition tends to become low because of its low surface free energy. Thus, an enhancement of the coated surface state of a coating film formed by coating a composition containing such a compound was demanded.